Crystal Structure Control of Zinc-Blende CdSe/CdS Core/Shell Nanocrystals: Synthesis and Structure-Dependent Optical Properties

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• 作者：Wennuan Nan ; Yuan Niu ; Haiyan Qin ; Fan Cui ; Yu Yang ; Runchen Lai ; Wanzhen Lin ; Xiaogang Peng
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：December 5, 2012
• 年：2012
• 卷：134
• 期：48
• 页码：19685-19693
• 全文大小：507K
• 年卷期：v.134,no.48(December 5, 2012)
• ISSN：1520-5126

文摘

Nearly monodisperse zinc-blende CdSe/CdS core/shell nanocrystals were synthesized by epitaxial growth of 1鈥? monolayers of CdS shell onto presynthesized zinc-blende CdSe core nanocrystals in one pot. To retain the zinc-blende structure, the reaction temperature was lowered to the 100鈥?40 掳C range by using cadmium diethyldithiocarbamate as a single-source precursor and primary amine as activation reagents for the precursor. Although the wurtzite counterparts grown under the same conditions showed optical properties similar to those reported in the literature, zinc-blende CdSe/CdS core/shell nanocrystals demonstrated surprisingly different optical properties, with ensemble single-exponential photoluminescence decay, significant decrease of photoluminescence peak width by the shell growth, and comparatively high photoluminescence quantum yields. The lifetime for the single-exponential ensemble photoluminescence decay of zinc-blende CdSe/CdS core/shell nanocrystals with 3鈥? monolayers of CdS shell was reproducibly found to be approximately 16.5 卤 1.0 ns.